A known type of header of a combine harvester comprises an auger for moving harvested crops from the lateral portions of the header towards the central area of the header where the crops are supplied to the entry port of the combine's feeder. The auger has a cylindrical body extending essentially along the full width of the header and provided with oppositely wound helical blades on both sides of the central area, so as to push the crops towards said central area. The auger is additionally provided with auger fingers configured to support the crops during their movement along the auger's longitudinal direction. In the central area especially, the auger fingers are important for guiding the crops effectively towards the entry port of the combine's inlet feeder. Similar auger systems are used in balers configured for gathering hay from the ground and forming rectangular or cylindrical bales.
The mechanism that is commonly in use in present day combines employs a hollow rotating tube with the helical blades attached to the outer surface, and auger fingers which are configured to rotate about a fixed time shaft that is itself eccentrically placed with respect to the tube's rotation axis. Usually the central auger fingers rotate about a time shaft that is distinct from the laterally placed time shafts of the lateral auger fingers. The location of the central time shaft is chosen so that the central auger fingers extend furthest out of the tube at the front of the auger, so as to support a load of crops during its movement towards the area underneath the auger tube and hence towards the feeder, and retract into the tube at the back side of the auger tube, thereby enabling the delivery of the crops into the feeder's entry port. As the fingers rotate about a fixed shaft, there is an inevitable dead zone where the crops are not supported by the auger fingers. As the size of combines and thus of the auger mechanisms increases, this dead zone equally increases in size, leading to an unacceptable decline in terms of the consistency of the crop delivery.